Photographic apparatus



May 27, 1969 A, M. SILVERMAN ETAL 3,446,127

PHOTOGRAPHIC APPARATUS Filed Oct. 14. 1966 Sheet of 2 INVENTOR,

fi wwn and 2M ATTORNEYS Filed on. 14, 1966 M y 1969 M.- SILVERMAN ET AL 3,446,127

PHOTOGRAPHIC APPARATUS Sheet 2 0152 INVENTOR.

fi wwn and m ATTORNEYS United States Patent 3,446,127 PHOTOGRAPHIC APPARATUS Allyn M. Silverman, Boston, and Charles W. Triggs, Lynn,

Mass., assignors to Polaroid Corporation, Cambridge,

Mass., a corporation of Delaware Filed Oct. 14, 1966, Ser. No. 586,884 Int. Cl. G03b 29/00 US. CI. 95-12 8 Claims ABSTRACT OF THE DISCLOSURE A collapsible viewing device attached externally to a camera for inspecting transparencies produced by the camera. The compact viewer has a triangular shape, with the transparency held in one leg so that the light passing through the transparency will be reflected from the base surface through the eyepiece in the opposite leg in a positive image.

A camera and film materials adapted to the production of mounted transparencies suitable for viewing by the device of the present invention are described in detail in the copending US. patent application Ser. Nos. 516,416 and 516,494, both filed Dec. 27, 1965, under the name of Rogers B. Downey, for Camera Apparatus and Photographic Film Assembly, respectively. Although not constituting a part of thepresent invention, a brief description of the general method of image formation in a film material usable in the above-reference camera fol lows.

A film assembly for forming a transparency of a type suitable for use with the device of the present invention includes photosensitive and image-providing components and a releasably-contained processing liquid. It is of a multilayer structure such that, after exposure, release of the liquid by the application of a compressive force to a liquid-containing element thereof and inhibition of the liquid into predetermined layers, including an exposed silver halide emulsion layer, provide a visible image. The image is formed by the diffusion transfer of image-forming substances to a designated image-receiving surface. Such a process is associated with cameras and film materials sold by Polaroid Corporation, Cambridge, Mass., USA. Processing is initiated by moving the film assembly between compressive means and, in the above-mentioned camera on which the device is mounted, involves mechanical transport means operating according to a pre determined program. A processing liquid suitable for use in forming the image may comprise an aqueous solution of a silver halide developer such as hydroquinone, a silver halide solvent of the type of sodium thiosulfate, and an alkaline substance such as sodium hydroxide. It may also preferably include a thickening or film-forming agent such as a synthetic polymer of the type of sodium carboxymethyl cellulose and, possibly, a high-molecular-weight polymeric mordant to facilitate the transfer process. In producing a black-and-white image, a latent image is developed; the exposed silver halide is reduced to silver, and the unreduced silver halide forms a soluble silver complex which is transferred from undeveloped areas to the image-receiving surface, the image being formed on the latter in silver. In the production of a color transparency, substances capable of forming dye images at the imagereceiving surface such as dyes, color couplers, or the like, may be employed in the transfer process. Or, a black-andwhite image in conjunction with a color screen may, advantageously, be employed to provide an image visible substantially in full color. Each film assembly, supplied as a unit of a film pack, already includes a mount which, after the assembly has been exposed and processed, en-

ables it to be mounted in a for projection purposes.

Where the completed print is of so-called miniature photographic dimensions as, for example, approximating those of a 35 mm. or so-called 2 x 2 frame of film, and where it is desired to ascertain the quality of a photographic image immediately following its completion, that is, for checkup purposes, a viewing means which provides both an effective illumination, a sharp rendition and an adequate magnification of the transparency constitutes an indispensable adjunct to the camera. Assuming the above considerations to be correct, it is of importance, also, that the viewing means shall be of little bulk; that it is collapsible for transport purposes, that it avoids an intrusion of extraneous light, and that it is rapidly erectile to a functional position for performing a quick survey of print quality immediately after the steps of exposure and processing. The device of the present invention possesses all of the foregoing advantages.

Objects of the invention are to provide an improved viewing device for incorporation with a miniature camera to enable the immediate viewing of a transparency which has been processed in and withdrawn from the camera to enable prompt correction of taking procedures; to provide a viewing device of a type comprising, respectively, a pivotal combined diffusing screen and transparency slide holder, an image-reflecting surface upon which a visible image of the transparency can be formed for viewing purposes, and a pivotal lens-board mounting a magnifying lens for viewing the reflected image; to provide a viewing device of the character described embodying at functional position a peaked light-shielding chamber formed by the screen, reflecting surface and lens board for substantially preventing the entrance of ambient light to the reflecting surface; to provide a viewing device, as characterized, including a foldable and releasable bellows element mounted across the open sides thereof for shielding the interior of the device relative to extraneous light and for preventing the entrance of dust or moisture thereinto; to provide a viewing device, as described, in which a horizontal base member carrying the reflecting surface is adapted to be mounted on a given portion of the camera with the diffusing means and the lens board being pivotally mounted at each of the base member so as to fold upon or pivot away from the latter for transport or operational use, respectively; to provide a device of the category stated in which the aforesaid pivotal elements are spring-biased to assume their functional positions thereby forming the peaked light-shielding chamber; to provide a device, as described, in which release and detent means enable the pivotal elements to assume their functional and non-functional positions; to provide a viewing device which automatically provides an operational position of its elements in response to actuation of a release button; to provide a viewing device of the character specified which is attachable to, and forms a compact assembly with a pivotal, semi-enclosing processing chamber of the camera; and to provide a viewing device which possesses a heightened light-gathering property and contributes to an ease of viewing a transparency mounted therein.

Other objects of the invention will in part be obvious and will in part appear thereinafter.

The invention accordingly comprises the apparatus possessing the construction, clombination of elements and arrangement of parts which are exemplified in the following detailed disclosure, and the scope of the application of which is indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings wherein:

FIGURE 1 is a diagrammatic perspective view of a conventional slide projector camera embodying the viewing device of the invention, the latter being at an erected functional position and a mounted transparency being positioned therein for view- FIG. 2 is a front view of a mounted photographic transparency of a type produced in the camera and ready for insertion in the slide-holder of the viewing device;

FIG. 3 is a fragmentary diagrammatic perspective v1ew of the viewing device folded upon a semi-enclosing processing chamber of the camera;

FIG. 4 is a diagrammatic perspective view of the viewing device, still folded upon the processing chamber but with the latter pivotally folded against the camera back for storage or transportation purposes; and

FIG. 5 is a diagrammatic perspective view of a modification of the viewing device incorporating self-erecting means and a light shielding bellows.

Referring now to the drawings, a miniature camera 10, and transparency viewing device 12 of the invention incorporated therewith is shown in FIG. 1 with the camera positioned, e.g., hand held, face up. At this nonpicture-taking position of the camera, its lens and shutter assembly 14 is uppermost, the semi-enclosing processing chamber 16 of the camera, pivotally mounted thereon at 17, is at laterally-extended functional position, and the transparency viewing device 12, mounted on the latter, is erected and ready for use.

The camera is to be understood as of the general type described in detail in the copending US. patent application Ser. No. 516,416 filed Dec. 27, 1965, for a camera apparatus in the name of Rogers B. Downey and application Ser. No. 588,358, filed Oct. 21, 1966, and now Patent No. 3,421,423 for a photographic apparatus, filed under the names of Rogers B. Downey and Gerald H. Cook. In brief, the camera, in addition to the elements 14 and 16, includes a viewfinder 18, a magazine 20 forming a part of the camera back and holding a plurality of film assemblies 22 in the form of a film pack, and a film-assembly processing mechanism positioned generally within rear housing portions of the camera. The terms front and rear, as used herein, refer to proximity or remoteness of the parts mentioned with respect to the front and rear of the camera.

The processing mechanism of the camera includes, in addition to the semi-enclosing chamber 16, a frame-like film-assembly advancing or propulsion means, not shown, which is attached at one end to the handle 28 and movable longitudinally within the camera in suitable guide means thereof. 'The propulsion means engages an edge of the foremost film assembly of the film pack which has been positioned at the focal plane and which has undergone photographic exposure. After its exposure, the film assembly is pushed between the pressure rolls 24 and 26 by manually actuating the handle 28. The handle 28 which has previously been pulled out to enable the ad vancing means to engage a trailing edge of the film assembly, is pushed inwardly to obtain the aforesaid advaneement of the film assembly between the pressure rolls. After leaving the pressure rolls, the film assembly is propelled, by continued pushing of the handle 28, through an exit aperture or slot 30, formed in the camera housing, and into the semi-enclosing chamber 16. One side of the film assembly, through which the exposure takes place is positioned against an opaque base 16a of the chamber. The other side of the film assembly is protected by a removable opaque sheet component thereof.

In passing between the pressure rolls, the processing liquid contained in the film assembly is released, as previously described and imbibed into the essential film layers, including the silver halide emulsion, for the few seconds required. While undergoing processing, it is held between the base 16a and marginal engaging flanges 16b of the processing chamber. After completion of the diffusion-transfer image-forming process within the film assembly, non-essential remaining portions of the film assembly, including the silver halide emulsion, are stripped away by grasping the break-off tab 32' of the film assembly mount and separating it, with attached exhausted film portions, from the remainder of the film assembly at the frangible portions 32a. This stripping away of non-essential exhausted portions of the film assembly is best accomplished while the latter is helcl within the processing chamber 16 by the engaging flanges 16b. After separation of the tab 32 and attached film portions, the exposed and processed film assembly includes the rigid slide mount 34 composed, for example, as was the unitary tab 32, of a suitable plastic material such as a polystyrene, an image-bearing portion or transparency 34, and a frame or mask 36 surrounding the transparency. The cut-out area 160 of the processing chamber base permits it to be readily grasped and removed from the chamber. The slide or transparency is then adapted to be inserted into the viewing device 12 for inspection purposes and, if found to be satisfactory, is ready for projection.

The transparency viewing device 12 comprises a platelike base member 37 fixedly attached to the base 16a of the processing chamber, a composite pivotal member 38 including a slotted slide-holder portion 40 and a diffusing screen portion 42 rotatablyattached by the pin 44 inserted in the curved tubular portion 36a of the base member 36, and a lens-board member 46 pivotally mounted by a pin 48 inserted in raised bored portions 16d of the processing-chamber base. One of the mounted transparencies or slides 22 is shown as positioned within the slide holder. A mirror 50 for providing a visible image of a mounted transparency is mounted on the base member 36 and a magnifying lens or eye-piece 52 is mounted in an aperture formed in the lens-board member. The latter member is biased toward the open position illustrated by a torsion spring 54 largely enclosed in the tubular housing 55 which, as shown, is an appendage of the base plate member 37. The composite member 38 may also be biased either toward the erected position shown or in an opposite direction by a torsion spring enclosed in the portion 36a. Alternatively, in a modified construction, no biasing means need be provided for either member 38 or 46.

At the erected functional position of the components of the viewing device shown in FIG. 1, the free-end extremities of the lens-board member 46 are frictionally or otherwise releasably engaged by cooperating portions of the member 38, as by detent or latch means at 56. The mirror 50 is slightly tapered, with its smaller end nearest the lens 52. Because of a difference in optical path length between the near and far ends of the mirror, when taken with the aforesaid tapered structure, the mirror and an image reflected thereat, appear, desirably, to be rectangular rather than tapered.

The viewing device 12 is folded to a non-functional or transport arrangement of its components by manually releasing the holding means at 56; pivoting the members 38 and 46 to a slightly more open position; pressing the member 46 downwardly against the base plate 36; and pressing the composite member 38 downwardly against member 46. The protruding lug elements 58 of the pivotal member 38 are thus caused to be inserted in the apertures 60 formed in the lens-board member 46 and to be releasably engaged by the latter, either frictionally or by associated spring-like fingers, not shown. The viewing device then appears as illustrated in FIG. 3. It will be noted that the portions 42a, 46a and 36a of the several superimposed members are so cut away or indented, as to overlie the cut-away portion of the processing chamber and provide ready access to a film assembly 22, when mounted in the latter, for facilitating its ready removal. In FIG. 4, the semi-enclosing processing chamber 16 has been pivoted to a closed nonfunctional position against the film-holding chamber or magazine 20, carrying the folded viewing device 12 with it. The processing chamber 16 is maintained at a closed position by an engaging element comprising suitable spring means, not shown, biasing it toward the magazine, attached respectively to camera and processing-chamber portions, or by detent means, not shown, in each instance complementary portions or components of the engaging element. FIG. illustrates the cooperative carrying or transport position of the camera and the viewing device 12.

In FIG. 5, a modification 12a of the viewing device is illustrated, its principal differences with respect to the structures above-described being an enclosing bellows 62 and a self-erecting mechanism. The bellows 62 has a single fold at 62a and is composed of a flexible, opaque, plastic sheet material such, for example, as a polypropylene.

The self-erecting mechanism includes a fiat spring 64 which bears against a curved surface of a laterally-extending appendage 66a of the lens board 66, thus biasing the latter, pivotally mounted at 67, to an open or erect position. An elongated slot 68 is formed in an inner surface of the side support member 7011 of the composite member 70 which includes a unitary diffusing screen and slide holder in superimposed relation. The member 70 is pivotally mounted at 71 on a base member 72. The latter includes a reflecting element, not shown, which is similar to that described relative to FIG. 1. A pin 74 extends laterally from the lens board 66 and is positioned for slidable movement within the slot 68. When the lens board is erected from its initial folded position against the base member 72 by the spring 64, the pin 74 is caused to travel along the slot 68, from the extremity 68a to the extremity 68b thereof. This movement of the pin 74 causes the composite member 70 to open from a folded position to the erect position shown. The members 66 and 70 are held at the closed position through engagement of the slightly-flared male latch component 76 with the undercut female latch component 78. The latch element 76 is mounted on a flat spring 80 which, in turn, is fastened at one end by the rivets -82 to the base member 72, its opposite or free end being bent slightly away from the base member. An actuating button 84 is positioned at the free end of the spring element 80-. Assuming the lens-board member 66 and the composite member 70 to be at folded position, with spring 64 thereby being fully tensioned, manual pressure on the button 84 disengages the latch component 76 from the latch component 78. The spring 64 then assumes control and the viewing device 12a opens to provide the functional erected disposition of its members shown.

Materials suitable for employment in the viewing device structures of FIGS. 1 and 5 are as follows. The diffusing component of the composite member 38 or 70 may suitably be composed of an acrylic or, for example, of a material known as opal acetate. The slide-holder component thereof may be composed of an opaque acetal such, for example, as the substance Delrin, sold by E. I. du Pont de Nemours (30., Wilmington, Del., U.S.A. The two components may be joined together to form a unitary structure by an application of heat or an ultrasonic treatment. The base member 16 or 72 may be composed of the aforesaidfDelrin, of a styrene, or of some other appropriate plastic. The materials named provide a low frictional factor in conjunction with a film-assembly mount composed, for example, of a polystyrene, thus facilitating the insertion and removal of a slide relative to the slideholder component. The reflector 50 may suitably be composed of glass having a reflecting coating or of a chromeplated steel. The eye-piece 52 is a positive lens having, for example, a focal length of two and one-half inches. In the constructions shown, it will be noted that the diffusing component serves also, in part, as an element of the slide-holder component.

The triangular form of the erected viewing device provides a somewhat darkened interior with respect to the admittance of unwanted ambient or extraneous light, thus heightening the effectiveness of the functional light which passes, in turn, through the diffusing component 42 and transparency 22; is transmitted as image-forming rays to the mirror 50 where the image is reversed, and thence is reflected to the eye-piece 52. The acute angular disposition of the composite member 38, comprising the diffusing screen and holding the transparency, facilitates the entrance of a maximum amount of the aforesaid functional light. In other words, more light is readily gathcred than would be the case were the member 38 posi tioned vertically and the mirror 50 dispensed with and, accordingly, the image brightness is heightened. Shielding of the interior of the device is, of course, greatly augmented by the addition of the bellows 62, and it is to be understood that a bellows may be included with the device 12, as well as with the device 12a. The acute angular position of the lens-board and eye-piece 52 contributes to an ease of viewing also, it apparently being somewhat more natural for the eye to focus generally downwardly in the viewing process. While, in the illustrations, the lens board is shown as first pivoted to a closed position, it will be appreciated that a modification of structure could permit a reverse order of pivotal movement of the two members. However, the order described is preferred because the underlying lens is protected.

Since certain changes may be made in the above apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A photographic-transparency viewing device for incorporation with a camera, especially one of a miniature type including means for processing a film assembly to produce said transparency, said viewing device permitting an immediate inspection of said transparency following its production and comprising a plate-like base member fixedly attached to an external surface of said camera, reflecting-surface means affixed to the exposed surface of said base member providing a reflected image of said transparency, a composite member including in superimposed relation and in order of light transmittal a light-diffusing screen and slide holder means, means pivotally mounting said composite member at one end of said base member, a lens-board member having mounted in an aperture thereof a positive lens independent of the objective of said camera and constituting an eye-piece, means pivotally mounting said lens-board member at the other end of said base member, a first engaging means for releasably holding the free non-pivotally-mounted extremities of said composite and lens-board members in mutually engaged relation at an operational position, namely, when pivoted toward one another to assume acute angles such that said device assumes a triangular conformation providing a heightened gathering of functional light but with its interior partially shielded against an entrance of ambient light, said functional light being transmitted through said diffusing screen and a transparency positioned in said slide holder, and thence as image-forming rays to said reflecting-surface means, from which, with reversed relation of said rays, it is reflected to said eyepiece lens, and a second engaging means for releasably holding said composite and lens-board members at a nonoperational transport position folded against one another and said camera surface.

2. A device, as defined in claim 1, wherein at least one of said composite and lens-board members is biased for pivotal movement in a given direction by torsion-spring means cooperating with said means pivotally mounting said members.

3. A photographic-transparency viewing device for incorporation with a camera, especially one of a miniature type including means for processing a film assembly to produce said transparency, said viewing device permitting an immediate inspection of said transparency following its production and comprising a plate-like base member fixedly attached to a surface of said camera, reflecting-surface means afiixed to the exposed surface of said base member, a composite member including in superimposed relation a light-diffusing screen and slide holder means, means pivotally mounting said composite member at one end of said base member, a lens-board member having mounted in an aperture thereof a positive lens constituting an eye-piece, means pivotally mounting said lensboard member at the other end of said base member, opaque bellows means so interconnecting said composite and lens-board members as to provide a complete shield ing of the interior of said device against an entrance of ambient light, a first engaging means for releasably holding the free non-pivotally-mounted extremities of said composite and lens-board members in mutually engaged relation at an operational position, namely, when pivoted toward one another to assume acute angles such that said device assumes a triangular conformation providing a heightened gathering of functional light but with its interior partially shielded against an entrance of ambient light, said functional light being transmitted through said diffusing screen and a transparency positioned in said slide holder, and thence as image-forming rays to said reflecting-surface means, from which, with reversed relation of said rays, it is reflected to said eye-piece lens, and a second engaging means for releasably holding said composite and lens-board members at a non-operational transport position folded against one another and said camera surface.

4. A photographic-transparency viewing device for incorporation with a camera, especially one of a miniature type including means for processing a film assembly to produce said transparency, said viewing device permitting an immediate inspection of said transparency following its production and comprising a plate-like base member fixedly attached to a surface of said camera, reflectingsurface means affixed to the exposed surface of said base member, a composite member including in superimposed relation a light-diffusing screen and slide holder means, means pivotally mounting said composite member at one end of said base member, a lens-board member having mounted in an aperture thereof a positive lens constituting an eye-piece, means pivotally mounting said lens-board member at the other end of said base member, portions of said reflecting surface means approaching said lensboard member being continuously wider than portions thereof approaching said composite member to provide a tapered configuration of said reflecting-surface means, a first engaging means for releasably holding the free nonpivotally-mounted extremities of said composite and lensboard members in mutually engaged relation at an operational position, namely, when pivoted toward one another to assume acute angles such that said device assumes a triangular conformation providing a heightened gathering of functional light but with its interior partially shielded against an entrance of ambient light, said functional light being transmitted through said diffusing screen and a transparency positioned in said slide holder, and thence as image-forming rays to said reflecting-surface means, from which, with reversed relation of said rays, it is reflected to said eye-piece lens, and a second engaging means for releasably holding said composite and lensboard members at a non-operational transport position folded against one another and said camera surface.

5. A photographic-transparency viewing device for incorporation with a camera, especially one of a miniature type including means for processing a film assembly to produce said transparency, said viewing device permitting an immediate inspection of said transparency following its production and comprising a plate-like base member fixedly attached to a surface of said camera, reflecting-surface means affixed to the exposed surface of said base member, a composite member including in superimposed relation a light-dilfusing screen and slide holder means,

means pivotally mounting said composite member at one end of said base member, a lens-board member having mounted in an aperture thereof a positive lens constituting an eye-piece, means pivotally mounting said lens-board member at the other end of said base member, a first engaging means for releasably holding the free non-pivotally-mounted extremities of said composite and lens-board members in mutually engaged relation at an operational position, namely, when pivoted toward one another to assume acute angles such that said device assumes a triangular conformation providing a heightened gathering of functional light but with its interior partially shielded against an entrance of ambient light, said functional light being transmitted through said diffusing screen and a transparency positioned in said slide holder, and thence as image-forming rays to said reflecting-surface means, from which, with reversed lelation of said rays, it is reflected to said eye-piece lens, and a second engaging means for releasably holding said composite and lensboard members at a non-operational transport position folded against one another and said camera surface, said plate-like base member being attached to a pivotal processing chamber of said camera whereby said chamber and said viewing device mounted thereon and at said folded position can be pivoted against the housing of said camera to provide a minimum bulk thereof for transport purposes.

6. A photographic-transparency viewing device comprising a plate-like base member, reflecting-surface means affixed to the exposed surface of said base member, a composite member including in superimposed relation, a light-diffusing screen and slide-holder means, means pivotally mounting said composite member at one end of said base member, a lens-board member having mounted in an aperture thereof a positive lens constituting an eye-piece, means pivotally mounting said lens-board member at the other end of said base member, a first engaging means for releasably holding the free non-pivotally-mounted extremities of said composite and lens-board members in mutually engaged relation at an operational position, namely, when pivoted toward one another to assume acute angles such that said device assumes a triangular conformation providing a heightened gathering of functional light which is transmitted through said diffusing screen and a transparency positioned in said slide holder, and thence as image-forming rays to said reflecting-surface means, from which, with reversed relation of said rays, it is reflected to said eye-piece lens, opaque bellows means so interconnecting said composite and lens-board members as to provide a complete shielding of the interior of said device against an entrance of ambient light, and a second engaging means for releasably holding said composite and lensboard members folded against one another at a nonoperational transport position.

7. A photographic-transparency viewing device for incorporation with a camera of a type including means for processing a film assembly to produce said transparency, said viewing device permitting an immediate inspection of said transparency following its production and comprising a plate-like base member fixedly attached to a surface of said camera, reflecting-surface means aflixed to the exposed surface of said base member, a composite member including a light-diffusing screen and slide-holder means, a lens-board member including a positive lens mounted in an aperture thereof constituting an eye-piece, means pivotally mounting said composite and lens-board members at opposite ends of said base member, flexible bellows means attached to said composite and lens-board members and positioned across the open sides of said device lying therebetween, and complementary latching means incorporated with a given pair of said members for, alternatively, holding said members at an operational erected position providing a triangular conformation, with said base member as the base thereof and said composite and lens-board members acutely angled with respect thereto, and for holding said members at a non-operational position folded against said camera surface, said triangular conformation providing a heightened light-gathering property of said device and an ease of viewing said transparency when mounted therein.

8. A collapsible and self-erecting photographic-transparency viewing device for incorporation with a camera of a type including means for processing a film assembly to produce said transparency, said viewing device permitting an immediate inspection of said transparency following its production and comprising a plate-like base member fixedly attached to a surface of said camera, reflecting-surface means afiixed to the exposed surface of said base member, a composite member including a lightdiifusing screen and slide-holder means, a lens-board member including a positive lens constituting an eye-piece mounted therewithin, means pivotally mounting said composite and lens-board members at opposite ends of said base member, flexible bellows means attached to said composite and lens-board members and positioned across the open sides of said device lying therebetween, a flat spring for erecting said members fastened at one end to one side of said base member and so bearing against a portion of said lens-board member as to urge it toward erectile pivotal movement, an elongated slot formed in a side support of said composite member, a pin extending laterally from said composite member and slidably positioned in said slot, a fiat spring fastened at one end to a second side of said base member, a first latch component carried by a mid-portion of said last-named spring, a latch release button mounted at the free extremity of said last-named spring, and a second complementary latch component carried by a second side support of said composite member, said lens board and composite member being held together at folded transport position by said latch components when pivoted to their limits toward said base component against the bias of said first-named spring and, when said release button is pressed, pivoting to an open functional position under erectile bias applied by said first-named spring to said lens-board member and transferred to said composite member by said pin, the latter being caused to move slidably along said slot and cause said composite member to pivot likewise to an open functional position.

References Cited UNITED STATES PATENTS 576,435 2/ 1897 Eddy 95-12 XR 1,579,025 3/1926 Owens 350138 XR 2,854,903 10/ 1958 Land 95-12 XR 2,943,409 7/ 1960 Maiershofer. 3,097,584 7/1963 Wright 9512 NORTON ANSHER, Primary Examiner. L. H. MCCORMICK, JR., Assistant Examiner.

US. Cl. X.R. 350140, 250

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 446 ,127 May 27, 1969 Allyn M. Silverman et :11.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 39, "inhibition" should read imbibition Column 2, line 44, after "each" insert end line 62, "thereinafter" should read hereinafter Signed and sealed this 24th day of November 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

. Comn'nissioner of Patents Edward M. Fletcher, Jr.

Attcsting Officer 

